The peculiar craving to chew ice, known medically as pagophagia, is more than just a quirky habit. For individuals suffering from anemia, particularly iron deficiency anemia, it can be a compelling urge, almost an addiction. But Why Do Anemic People Eat Ice? This question has puzzled doctors and researchers for years, leading to fascinating theories that connect this unusual craving to the body’s response to iron deficiency.
Iron deficiency anemia occurs when the body lacks sufficient iron to produce hemoglobin, the protein in red blood cells that carries oxygen. Fatigue is a hallmark symptom, leaving sufferers feeling sluggish and mentally foggy. Interestingly, the link between iron deficiency and ice cravings has been observed for some time, with doctors noting that iron supplements often reduce or eliminate this craving. However, the underlying mechanism remained unclear until recent studies began to shed light on this intriguing phenomenon.
One compelling theory, explored in a study published in Medical Hypotheses, suggests that chewing ice may provide a temporary cognitive boost to individuals with iron deficiency, much like a cup of coffee. Melissa Hunt, a clinical psychologist from the University of Pennsylvania and the study’s author, recounted a personal anecdote that sparked her research. “I had a friend who was suffering from iron-deficiency anaemia who was just crunching through massive amounts of ice a day,” Hunt explained. “She said: ‘It’s like a cup of coffee. I don’t feel awake until I have a cup of ice in my hand.’”
To investigate this anecdotal evidence, Hunt and her team conducted a study comparing the cognitive performance of both anemic and healthy individuals. Participants underwent a standardized attention test, a common tool for diagnosing attention deficit hyperactivity disorder. Before the test, some participants were given ice to chew, while others drank lukewarm water.
The results were striking. Iron-deficient participants who drank water performed significantly worse on the attention test compared to healthy controls. However, the anemic individuals who chewed ice beforehand showed performance levels comparable to their healthy counterparts. For healthy participants, consuming ice had no noticeable impact on their test performance. This suggests that ice consumption might be uniquely beneficial for those with iron deficiency in terms of cognitive function.
Hunt clarified that this craving isn’t akin to a simple desire for a treat. “It’s not like craving a dessert. It’s more like needing a cup of coffee or that cigarette,” she stated, emphasizing the almost compulsive nature of pagophagia in anemic individuals.
The potential explanation for this cognitive boost lies in the “mammalian diving reflex.” This physiological response is triggered when the face, particularly around the eyes and nose, comes into contact with cold water. The diving reflex causes a slowing of heart rate and constriction of peripheral blood vessels, redirecting blood flow towards the vital organs, including the brain.
Think of marine mammals like whales and dolphins diving into cold water. Their bodies initiate this reflex to conserve oxygen and prioritize blood supply to the brain and heart. While less pronounced in humans, we still possess this vestigial reflex. Chewing ice, especially allowing the coldness to affect the face, might trigger this diving reflex, leading to an increased flow of oxygenated blood to the brain. For individuals with iron deficiency and consequently reduced oxygen-carrying capacity, this temporary surge in cerebral blood flow could translate to a noticeable improvement in alertness and cognitive function. However, in individuals with normal iron levels and sufficient oxygen supply, this effect would likely be negligible, explaining why ice didn’t boost cognitive function in healthy participants in the study.
Catherine Broome, a hematologist at Georgetown University School of Medicine, corroborates the clinical relevance of pagophagia. She routinely observes ice cravings in her iron-deficient patients and even uses the intensity of this craving as a clinical marker to monitor treatment progress. “As we replace a patient’s iron, the desire to chew ice will lessen, so it’s an easy symptom to follow in patients,” Broome noted. She found the study on cognitive boost fascinating and the diving reflex explanation plausible.
Michael Bromberg, a hematologist at Temple University, also acknowledges the commonality of pagophagia among iron-deficient patients. He highlights the often secretive nature of this craving, stating, “Patients tend to be somewhat secretive about these kinds of behaviours. You have to tease it out.” This secrecy might be due to the unusual nature of the craving and a lack of understanding about its connection to a medical condition.
It’s important to place pagophagia within the broader context of pica, a disorder characterized by persistent cravings for and consumption of non-nutritive substances or atypical foods. Pica can manifest in various forms, including cravings for clay, chalk, or even non-food items like cigarette butts. Pagophagia, specifically the craving for ice, is considered a subtype of pica. While pica is associated with nutritional deficiencies, particularly iron and zinc, the exact reasons behind these unusual cravings remain largely enigmatic. Interestingly, pica, including pagophagia, is observed in approximately half of iron-deficient individuals, indicating that other factors might also play a role.
While the mammalian diving reflex theory offers a compelling explanation for why anemic people eat ice and experience a temporary cognitive lift, further research is needed to fully unravel the complexities of pagophagia and its relationship with iron deficiency. Understanding this connection is crucial for healthcare professionals to recognize and address pagophagia as a potential indicator of underlying iron deficiency and to provide appropriate treatment and support to those affected. For individuals experiencing persistent ice cravings, especially when accompanied by fatigue or other symptoms of anemia, seeking medical advice is paramount to determine the underlying cause and receive necessary care.
